Blender not using selected compute device
It shows GPU core clock at 135MHz. There is something wrong with that. Usual clock speed of GTX750TI is 1020MHz. It could be that for some reason the driver crashes and it switches to some sort of a safe mode. Updating drivers would be first thing to do. I would try using it just after rebooting the PC. If it works just after a restart then it will be clear that the problem is indeed with the driver crashing. The GPU could be overclocked too much or it might be overheating or it might not be able to get enough power.